Rail profile grinding machine

A rail profile grinding machine, comprising a grinding head carrying an abrasive grinding tool mounted to rotate about an axis and capable also of describing an up/down movement parallel to its axis of rotation, the grinding head being carried by the central part of a chassis provided, at its ends, with means for running, guiding and fitting on a rail of a railroad track, the grinding machine also comprising motorized means for rotating the grinding tool about its axis and maneuvering means for moving the grinding machine back and forth in the longitudinal direction of the rail that is to be ground, the chassis pivoting with the grinding head about a longitudinal axis so as to provide a choice of grinding the top side of the rail, or the flank of the rail head on the inside of the track or the flank of the rail head on the outside of the track, wherein the motorized means for rotating the grinding tool consist of an internal combustion engine with horizontal output shaft, the engine being fixed to a support which is articulated, about a longitudinal axis, to a balancing assembly itself mounted to pivot about a longitudinal spindle on the chassis and designed to occupy, in use, a horizontal position by resting on the other rail of the track, while the horizontal output shaft of the engine is connected, via a transmission assembly, to the grinding head carried by the chassis in such a way as to limit the inclination of the engine to small angles.